Semantic 3D City Models Serving as Information Hub for 3D Field Based Simulations

A major challenge in the context of global urbanization is to make cities “smarter” in order to satisfy their increasing requirements to safety, environmental conditions and quality of living. This requires both the environmental and social processes taking place in cities to be perspicuous and predictable. Today, simulations from various disciplines like wind field or flood simulations, noise propagation, pollutant dispersion or explosion simulations have become essential tools for decision making in urban planning and analytics. A common simulation approach is the “Finite Volume”-method, where the observation area is partitioned into a regular grid of cells to solve partial differential equations numerically. 3D city models serve as reliable representation of the real world objects. In this study we present an approach for the integration of such field-based simulations with object-based, semantic 3D city models. It allows for automatically deducing a finite volume-based representation of arbitrary objects in 3D city models. The city model is used as an information hub between the systems. It serves both as the data source for the geometry representation of the simulation and its result storage. For this, the corresponding region is divided into equal cubes (voxels) and each voxel is tested against intersection with the city objects. Thus, each voxel inherits the semantics of its intersecting city object, which ensures that a) the voxel holds the characteristics of its counterpart and b) the results of the simulation runs can be aggregated per object and stored back in the city model. Visualization and result analysis is of crucial importance, since highly tailored simulation tools do not offer interactive access to the simulation results. In contrast, the frameworks for 3d city models provide comprehensive tools for both visualization and intuitive analysis. They allow even for non-expert users to assess the information generated by the simulation tools. The proposed approach is introduced and evaluated on the example of a blast simulation and implemented using a 3D city model according to the international standard CityGML. It is realized in an Open Source plug-in for the 3D geodatabase software 3DCityDB.     «

A major challenge in the context of global urbanization is to make cities “smarter” in order to satisfy their increasing requirements to safety, environmental conditions and quality of living. This requires both the environmental and social processes taking place in cities to be perspicuous and predictable. Today, simulations from various disciplines like wind field or flood simulations, noise propagation, pollutant dispersion or explosion simulations have become essential tools for decision mak...     »